Primary beer gushing is defined as the wild and uncontrolled overfoaming of packaged beer induced by contaminated raw materials as barley and malt. It is generally admitted that most probably amphipathic molecules such as hydrophobins and non-specific lipid transfer proteins (ns-LTPs) are responsible for this phenomenon. These molecules are synthesized by moulds and by vegetal tissues respectively in order to modify the polarity of surfaces and the solubility of molecules. At present, hydrophobins are extensively studied as they are considered as the major responsible molecules involved in primary gushing. This review compiles the relevant fundamental physical and chemical properties of CO2 and experimental observations at laboratory and pilot scale.0 till 4.0 ATU of CO2 )..

Aged beer flavour was studied by ageing a lager beer in different conditions (varying temperature-time profiles, different oxidative conditions and varying pH and ethanol concentrations). This led to beers with a varying aged flavour, which could be explained by differences in the reaction rate of ageing reactions. High temperatures, oxidative conditions and to a lesser extent, a lower pH, accelerated beer ageing. Enhanced (E)-2-nonenal formation probably led to the greater perception of cardboard flavour after ageing at high temperatures. Madeira flavour was only perceived after ageing at 20 °C and ribes flavour was mainly perceived in oxidatively aged beer..

1) After quite a long winter, spring work was started in the hop fields some days ago. Some farmers are still fastening the wires for training the hop vines. Normally, this work will have already been done whilst the ground is frosty in winter in order to avoid surface damage to the soil by heavy machinery.

The Research Center Weihenstephan for Brewing and Food Quality at the Technical University Munich reacts to numerous enquiries from different breweries all over the world concerning:

Traditionally used by the British cask ale brewers to add a strong, distinctive hop character to beer in cask, this practice has also now been adopted by the world craft brewing sector to produce a range of significantly different products.

New industrial brewing yeasts*1 have been generated by introduction of two genes involved in valine biosynthetic pathway in order to clarify their roles for the reduction of diacetyl content in beer. The Saccharomyces cerevisiae genes as well as lager*2 genes both BAT1 (encoding branched-chain amino acid aminotransferase) and BAT2 (encoding branched-chain amino acid aminotransaminase) have been transferred into brewer’s yeast. Within this approach it was possible to decrease diacetyl levels at the end of main fermentation without affecting the by-product profile of the beer negatively. Furthermore, our results pointed to the regulation of these genes concerning diacetyl formation.

BrewingScience - Monatsschrift für Brauwissenschaft, 63 (January/February 2010), pp. 6-13

The formation and removal of dimethyl sulfide (DMS) was studied during a new method for wort production, without classic wort boiling. This was compared with classic brewing trials comprising one hour of wort boiling. The new wort production method consists of fine milling of malt under water to minimize LOX reactions, mashing-off at 95 °C, membrane assisted thin bed filtration, in-line injection of clean steam in the filtered wort and stripping of the wort while entering the combination vessel (‘boiling’ kettle/decantor), optional clean steam injection during filling of the combination vessel, and finally decantation of the hot trub in the same combination vessel.5 hours as compared to at least 3.5 hours for classic brewing using the same brewing line..

Lactobacillus brevis comprises strains with diverse metabolic capabilities. Some specialized strains can grow even in highly hopped pilsner beers without the need of long term adaptation. Other strains develop tolerance upon prolonged hop exposition or remain sensitive. In this communication genetic analyses, proteomics and physiological tests in beer as well as studies in membrane physiology and cell wall composition are reviewed, which are useful to differentiate L. brevis strains along their beer spoiling potential and to elucidate decisive marker traits for categorizing beer spoiling L. brevis along their relevance for the brewer. Hop adaptation in L. brevis TMW 1. A simple test for mangenese efflux provides a useful tool for categorization of beer spoiling L. brevis..

Dietary antioxidants are believed to be effective in the prevention of oxidative stress related diseases (eg. cancer and cardiovascular diseases). Polyphenols are widely recognized as potent antioxidants as they can scavenge reactive oxygen species (ROS). The hop plant (Humulus lupulus L.), used in a variety of health applications and indispensible as a beer ingredient, is an interesting source of polyphenolic antioxidants including tannins, flavonol glycosides and prenylated flavonoids. In addition, also hop oil and hop acids (including downstream products) have been reported as potent antioxidants. In this investigation, the radical scavenging activity of hop products (including different extracts and downstream products) was investigated using two different antioxidant assays: the ORAC to study the peroxyl radical scavenging capacity and HORAC to investigate the hydroxyl radical scavenging capacity. Quercetin and a grape extract containing oligomeric proanthocyanidins (OPC) were used for comparison. The peroxyl radical scavenging capacities of prenylated flavonoids were highly analogous to quercetin and OPC equaling 5–10 Trolox equivalents. The hydroxyl radical scavenging capacities of Xantho-FlavTM products correlated with the concentration of xanthohumol and pure xanthohumol (> 95 %) corresponded to about 60 Trolox equivalents, which is 10–20 times higher than that of quercetin and OPC.

Addition of stabilisation products in the upstream brewing process is a very convenient way of physico-chemical stabilisation without the need for extra filtration or the risk of beer losses. Therefore, in this study the use of appropriate stabilisation products upstream the brewing process, more specifically at the end of wort boiling, have been evaluated in relation to improved colloidal stability. Applications of PVPP (Polyclar 10, ISP) and gallotannins (Beerotan Q, BFTI) have been investigated. The lowest gallotannin levels (wort boiling: 5 g/hL; contact time in boiling kettle: 3 minutes) are already sufficient to obtain enhanced stability due to adequate removal of haze- sensitive proteins. Furthermore, the addition of 10 g/hL PVPP has an explicit effect on the amounts of polyphenols, which results in an improved colloidal stability.

One of the largest and most modern malthouses in the world is located in a country of tropical climate, where barley cultivation remains an option for few farmers: in the southern region of Brazil, in Paraná State, the Agrária Cooperative has recently inaugurated Agromalte’s expansion. Founded in the 1950s by Danube-Swabian immigrants, the cooperative has shown that the investment in agricultural research and technology was responsible for making Agromalte a synonym for top quality malt.